To reproduce:
1. Open attached project.
2. Drag and drop 'game objects' in hierarchy for some time. Just like in attached video.

To reproduce in a new project:
1. Add some objects to your scene.
2. Drag and drop them in the hierarchy until you get a crash.

Expected result: Object is dragged to the right place in a hierarchy.
Actual result: Editor sometimes crashes.

Reproducible with: Unity 5.4.0, Unity 5.4.2
Not reproducible with: Unity 5.3.1

Fixed in Unity 5.5

Crash Call Stack:

Transform::UpdateTransformAccessors
Transform::SetParent
SetTransformParentUndo
HandleSetTransformFatherDragAndDrop
DragAndDropForwarding::ForwardDragAndDrop
InternalEditorUtility_CUSTOM_HierarchyWindowDrag
UnityEditorInternal.InternalEditorUtility:HierarchyWindowDrag
UnityEditor.GameObjectsTreeViewDragging:DoDrag
UnityEditor.TreeViewDragging:DragElement
UnityEditor.TreeView:HandleUnusedMouseEventsForItem
UnityEditor.TreeView:DoItemGUI
UnityEditor.TreeView:IterateVisibleItems
UnityEditor.TreeView:OnGUI
UnityEditor.SceneHierarchyWindow:DoTreeView
UnityEditor.SceneHierarchyWindow:OnGUI
object:runtime_invoke_void__this__
mono_get_runtime_build_info
mono_runtime_invoke
mono_runtime_invoke_array
mono_register_jit_icall
System.Reflection.MonoMethod:InternalInvoke
System.Reflection.MonoMethod:Invoke
System.Reflection.MethodBase:Invoke
UnityEditor.HostView:Invoke
UnityEditor.DockArea:OnGUI
object:runtime_invoke_void__this__
mono_get_runtime_build_info
mono_runtime_invoke
ScriptingInvocationNoArgs::Invoke
MonoBehaviourDoGUI
IMGUIModule::MonoBehaviourDoGUI
MonoBehaviour::DoGUI
GUIView::OnInputEvent
-[GUIOpenGLView doDrag:type:]
-[GUIOpenGLView performDragOperation:]
NSCoreDragReceiveMessageProc
DoMultipartDropMessage
DoDropMessage
SendDropMessage
DragInApplication
CoreDragStartDragging
-[NSCoreDragManager _dragUntilMouseUp:accepted:]
-[NSCoreDragManager dragImage:fromWindow:at:offset:event:pasteboard:source:slideBack:]
-[NSWindow(NSDrag) dragImage:at:offset:event:pasteboard:source:slideBack:]
-[DelayedDrag DoStart]
DragAndDrop::ApplyQueuedStartDrag
GUIView::OnInputEvent
-[GUIOpenGLView mouseDragged:]
-[NSWindow(NSEventRouting) _reallySendEvent:isDelayedEvent:]
-[NSWindow(NSEventRouting) sendEvent:]
-[NSApplication(NSEvent) sendEvent:]
-[EditorApplicationPrincipalClass sendEvent:]
-[NSApplication run]
NSApplicationMain
EditorMain
main
start